1. Field of the Invention
The present invention relates to a linear-displacement module for automatic machines and more precisely to a linear-displacement module intended to constitute a lateral face of a carriage holding an automatic machine such as may be found on a gantry used for welding or assembling parts.
2. Description of the Prior Art
Carriages and gantries permitting displacement of a tool, a workpiece or a machine part in a plane X, Y are well known. In general, a first carriage permits displacements parallel to an axis X'OX. These displacements may amount to several meters. Since the carriage can be very wide, it is necessary to synchronize its two ends. This is generally done by mechanical means. The two ends are controlled, for instance, by two screws positively driven by the same motor. This first carriage, which moves along the axis X'OX, must be wide, between 1.5m and 3m, for it must in turn carry the guide rails parallel to the direction Y'OY, perpendicular to X'OX, so that a second carriage can move thereon along the axis Y'OY. The displacements of this second carriage may themselves be on the order of a meter or more. The carriage moving in the Y'OY direction may be much narrower than the first carriage, since it generally has to support only the means for moving a tool or part along an axis Z'OZ perpendicular to the XOY plane.
Different elements are used at present in realizing these carriages. The two displacement elements of the carriage moving in the X'OX direction are different from one another and are different, in turn, from the corresponding elements of the carriage for the Y'OY direction. This multiplicity of basic devices leads to high costs and the inability to respond rapidly to a particular order from a customer. Moreover, if it is desired to have these elements in stock, a great deal of space is required and the money tied up in these stocks is likewise very great.